Amongst operation lever structures of work machines, there is known in the art and disclosed in Japanese Utility Model Application Laid-Open Publication No. 64-114 (JP-U 64-000114 A) an operation lever structure having an operation lever swingably provided to a handle, a link disposed between the operation lever and the handle, one end of the link rotatably attached to the handle, the other end moveably supported on the operation lever, and an operation cable connected to the link.
Rollers are rotatably provided to the other end of the link of the operation lever structure, and the rollers are moveably supported on a bottom part of the operation lever. Accordingly, when the operation lever is gripped and pulled toward the handle, the rollers move along the bottom part of the operation lever, whereby the link moves in a swinging motion around the one end.
According to the above described operation lever structure, gripping the operation lever and pulling toward the handle enables the link to move in a swinging motion and the operation cable to be operated (pulled). Operating (pulling) the operation cable makes it possible to switch between working and stopping operations, such as for braking and clutching.
In a state in which the operation cable is operated (pulled) by the link, the operation cable approaches the one end of the link. Therefore, a decrease is seen in the returning force of the link produced by the reactive force of the operation cable, and the gripping force required for the operator to keep the operation lever in the working position can be minimized.
Therefore, it is conceivable that dirt, rocks, and other foreign matter can enter the bottom part of the operation lever while work is being performed by the work machine. In a case in which foreign matter has entered and accumulated in the bottom part, it becomes difficult for the rollers to move smoothly along the bottom part, and the operability of the operation lever is compromised.